how do i treat this comb issue/injury?

i sprung this chicken from a local shelter today. it looks okay except that the comb seems to be a bit scabby. any ideas as to the nature of this problem (parasites, injury, infection?) and the best way to treat it?
this is what the rest of the chicken looks like:

It doesn't look that bad at all. It should come off within a week or so. Some looks like it already has come off. Don't worry about it. Do check for mites and lice though as that is something that would suck to bring to the flock.